Silicon and other semiconductor nanowires have potential uses in future nanoelectronic, nanophotonic, and sensing devices. One method of forming these wires is the “vapor-liquid-solid” (VLS) technique in which a liquid metal nanoparticle catalyzes the decomposition of a gas, such as silane, dichlorosilane, silicon tetrachloride, or germane, which is a source of the desired nanowire-forming material, such as silicon, germanium, indium phosphide, etc.
For many applications, the diameter of the nanowire must be controlled. The diameter of the nanowire is expected to depend on the size of the nanoparticle on which the wire is grown. Two methods of controlling the nanowire diameters are (1) controlling the nanoparticle diameters and their distribution, and (2) growing nanowires on a size-selected portion of the nanoparticle distribution. Most approaches to nanowire-diameter control focus on the former method. Size control of the nanoparticles is feasible for some materials, especially when those materials are formed ex-situ. However, it is difficult if the nanoparticles are formed in-situ to avoid air exposure between nanoparticle formation and nanowire growth.
Thus, there is a need for an improved method of growing nanowires.